U.S. patent application number 09/759506 was filed with the patent office on 2002-07-18 for automatic dross removal apparatus and method.
Invention is credited to McDonald, David M., Morris, James M., Willis, Scott.
Application Number | 20020092897 09/759506 |
Document ID | / |
Family ID | 25055906 |
Filed Date | 2002-07-18 |
United States Patent
Application |
20020092897 |
Kind Code |
A1 |
Morris, James M. ; et
al. |
July 18, 2002 |
Automatic dross removal apparatus and method
Abstract
An automatic dross removal apparatus, which can be used with a
solder wave apparatus, is provided, that generally includes a
reservoir having a cavity for containing liquid solder, dross
removal apparatus having a first end extending within the cavity of
the reservoir for removing dross on the surface of the liquid
solder, and a motor engaged with the dross removal apparatus. In
one embodiment of the invention, the dross is automatically removed
by a conveyor driven by a motor. In another embodiment of the
invention, the dross is automatically removed by a motor driven
receptacle. Means for moving the dross from one part of the solder
reservoir to another, such as a pump, can be included. Preferably,
a computer is used to control the automatic dross removal. The
dross can be placed in a dross separation device which can include
apparatus for processing the dross to remove any remaining
solder.
Inventors: |
Morris, James M.; (Lebanon,
MO) ; Willis, Scott; (Camdenton, MO) ;
McDonald, David M.; (Camdenton, MO) |
Correspondence
Address: |
A. Jason Mirabito, Esq.
MINTZ, LEVIN, COHN, FERRIS,
GLOVSKY and POPEO, P.C.
One Financial Center
Boston
MA
02111
US
|
Family ID: |
25055906 |
Appl. No.: |
09/759506 |
Filed: |
January 12, 2001 |
Current U.S.
Class: |
228/256 ;
228/102; 228/13; 228/33 |
Current CPC
Class: |
B23K 3/08 20130101 |
Class at
Publication: |
228/256 ; 228/13;
228/33; 228/102 |
International
Class: |
B23K 001/20; B23K
020/08; B23K 035/12 |
Claims
What is claimed is:
1. An automatic dross removal apparatus for a reservoir having a
cavity for containing liquid solder, the apparatus comprising: a
conveyor having a first end extending within the cavity of the
reservoir for removing dross on the surface of the liquid solder;
and a motor adapted to drive the conveyor for removing the dross
from the reservoir.
2. The automatic dross removal apparatus of claim 1, wherein the
conveyor is an endless belt.
3. The automatic dross removal apparatus of claim 2, wherein the
conveyor has a plurality of angle brackets being attached to a
surface of the endless belt for engaging the dross.
4. The automatic dross removal apparatus of claim 1, in combination
with a dross separation device being adjacent a second end of the
conveyor for separating solder from the dross collected from the
automatic dross removal apparatus.
5. The automatic dross removal apparatus and dross separation
device of claim 4, wherein the dross separation device comprises: a
first portion; a second portion being in a movable relation to the
first portion, one of the first and second portions having a
perforated section for allowing the liquid solder to pass
therethrough; and means for moving the first portion in relation to
the second portion.
6. The automatic dross removal apparatus of claim 5, wherein the
means for moving the first portion in relation to the second
portion comprises a piston operatively connected to a second
motor.
7. The automatic dross removal apparatus of claim 1, further
comprising a computer connected to the motor for controlling the
conveyor.
8. An automatic dross removal apparatus for a reservoir having a
cavity for containing liquid solder, the apparatus comprising: a
conveyor having an endless belt and a first end extending within
the cavity of the reservoir for removing dross on the surface of
the liquid solder; a motor adapted to drive the conveyor for
removing the dross from the reservoir; a computer electrically
connected to the motor for controlling the motor; and a dross
separation device.
9. The automatic dross removal apparatus and dross separation
device of claim 8, wherein the dross separation device comprises: a
first portion; a second portion being in a movable relation to the
first portion, one of the first and second portions having a
perforated section for allowing the liquid solder to pass
therethrough; and means for moving the first portion in relation to
the second portion.
10. An automatic dross removal apparatus for a reservoir having a
cavity for containing liquid solder, the apparatus comprising: a
skimmer having a first end extending within the cavity of the
reservoir and being movable within the reservoir for moving dross
on the surface of the liquid solder out of the reservoir; a motor
adapted to move the skimmer for removing the dross from the
reservoir; and means for moving the dross within the reservoir
towards the skimmer.
11. The automatic dross removal apparatus of claim 10, wherein the
means for moving the dross is one or more pumps.
12. The automatic dross removal apparatus of claim 10, wherein the
means for moving the dross is one or more sloped channels.
13. The automatic dross removal apparatus of claim 10, in
combination with a dross separation device being adjacent a second
end of the conveyor for separating solder from the dross collected
from the automatic dross removal apparatus.
14. The automatic dross removal apparatus and dross separation
device of claim 10, wherein the dross separation device comprises:
a first portion; a second portion being in a movable relation to
the first portion, one of the first and second portions having a
perforated section for allowing the liquid solder to pass
therethrough; and means for moving the first portion in relation to
the second portion.
15. An automatic dross removal apparatus for a reservoir having a
cavity for containing liquid solder, the apparatus comprising: a
skimmer having a first end extending within the cavity of the
reservoir and being movable within the reservoir for moving dross
on the surface of the liquid solder and out of the reservoir; a
motor adapted to move the skimmer for removing the dross from the
reservoir; at least one channel for moving the dross within the
reservoir towards the skimmer; a computer electrically connected to
the motor for controlling the motor; and a dross separation device
for separating solder from the dross collected from the automatic
dross removal apparatus.
16. The automatic dross removal apparatus and dross separation
device of claim 15, wherein the dross separation device comprises:
a first portion; a second portion being in a movable relation to
the first portion, one of the first and second portions having a
perforated section for allowing the liquid solder to pass
therethrough; and means for moving the first portion in relation to
the second portion.
17. The automatic dross removal apparatus of claim 16, wherein the
means for moving the first portion in relation to the second
portion comprises a piston operatively connected to a second
motor.
18. A method for automatically removing dross from a solder
reservoir having a cavity for containing liquid solder, the method
comprising: providing a conveyor having a first end extending
within the cavity of the reservoir; providing a motor adapted to
drive the conveyor; removing dross on the surface of the liquid
solder by controlling the motor to drive the conveyor and collect
the dross.
19. The method of claim 18, further comprising: providing a dross
separation device being adjacent a second end of the conveyor; and
separating excess solder from the removed dross by placing the
dross collected from the automatic dross removal apparatus into the
dross separation device.
20. The method of claim 18, further comprising: providing a
computer electrically connected to the motor; and controlling the
motor using the computer.
21. A method for automatically removing dross from a solder
reservoir having a cavity for containing liquid solder, the method
comprising: providing a skimmer having a first end extending within
the cavity of the reservoir and being movable within the reservoir
providing a motor adapted to move the skimmer; moving the dross
within the reservoir towards the skimmer; and moving dross on the
surface of the liquid solder out of the reservoir by driving the
motor to move the skimmer and remove the dross from the
reservoir.
22. The method of claim 21, further comprising: providing a dross
separation device being adjacent a second end of the skimmer; and
separating excess solder from the removed dross by placing the
dross collected from the automatic dross removal apparatus into the
dross separation device.
23. The method of claim 21, further comprising: providing a
computer electrically connected to the motor; and controlling the
motor using the computer.
Description
FIELD OF THE INVENTION
[0001] The present application relates generally to apparatus and
methods for removing dross from the surface of liquid or molten
solder.
BACKGROUND OF THE INVENTION
[0002] During normal containment of liquid solder in a solder
reservoir such as that used by a wavesolder device, a metallic
oxide forms which is referred to as dross. The dross floats on the
solder surface and must periodically be removed from the solder
reservoir to prevent contamination of the solder. The manual
removal of the dross results in machine down time to remove the
dross from the solder reservoir. This machine down time can result
in a high cost of ownership due to frequent maintenance to remove
these oxides.
[0003] One prior art device is a wavesolder designed so that the
dross flows into an area at one end of the solder pot reservoir
such that a machine operator will manually scoop out the generated
dross into a basket for removal. However, the manual removal of the
dross can still be time consuming.
[0004] Other devices allow the removal of dross from the surface,
such as apparatus shown in U.S. Pat. Nos. 5,087,356 to Webb,
4,509,670 to Cammarata and 3,980,219 to Schmid. However, these
devices do not function optimally because they in part do not
provide for the reclamation of excess solder from collected
dross.
SUMMARY OF THE INVENTION
[0005] An automatic dross removal apparatus, which can be used with
a solder wave apparatus, generally includes a reservoir having a
cavity for containing liquid solder, dross removal apparatus having
a first end extending within the cavity of the reservoir for
removing dross on the surface of the liquid solder, and a motor
engaged with the dross removal apparatus. In one embodiment of the
invention, the dross is automatically removed by a conveyor driven
by a motor. In another embodiment of the invention, the dross is
automatically removed by a motor driven receptacle. Means for
moving the dross from one part of the solder reservoir to another,
such as a pump, a nozzle, a sloped surface or channel, a paddle or
a moving edge, can be included. Preferably, a computer is used to
control the automatic dross removal. The dross can be placed in a
dross separation device which can include apparatus for processing
the dross to remove any remaining solder.
[0006] An advantage of embodiments of the present invention is that
a machine having a reservoir of solder, such as a wavesoldering
device, does not have to be shut down to remove dross from the
surface of the solder.
[0007] Another advantage of embodiments of the present invention is
that dross can be removed from a solder reservoir without operator
interaction, which creates a more maintenance free machine.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a cross sectional side view of one embodiment of
an automatic dross removal apparatus in accordance with the
invention.
[0009] FIG. 2 is a front isometric view of a dross reclamation
device used in conjunction with the automatic dross removal
apparatus of FIG. 1.
[0010] FIG. 3 is a cross sectional side view of another dross
reclamation device used in conjunction with the automatic dross
removal apparatus of FIG. 1.
[0011] FIG. 4 is a front isometric view of another embodiment of an
automatic dross removal apparatus in accordance with the
invention.
[0012] FIG. 5 is a top view of the automatic dross removal
apparatus of FIG. 4.
[0013] FIG. 6 is a cross sectional side view of yet another
embodiment of an automatic dross removal apparatus in accordance
with the invention.
[0014] FIG. 7 is a front isometric view of the conveyor of the
automatic dross removal apparatus of FIG. 6.
DETAILED DESCRIPTION OF THE INVENTION
[0015] FIG. 1 shows an embodiment of the automatic dross removal
apparatus 10. The apparatus 10 includes a solder reservoir 12 and a
conveyor 14 that is driven by a motor 16. The reservoir 12 contains
liquid solder 18 which has dross 20 forming on its top surface. A
dross removal mechanism, such as a conveyor 22, has one end
protruding into the solder reservoir 12 to skim the dross 20 from
the surface of the solder 18 and carry it on the conveyor. The
conveyor 14 is driven by a motor 28 that drives a sprocket 30 that
engages and drives the endless belt or chain of the conveyor for
removing the dross from the pot. The conveyor can have one or more
brackets 15, such as an angle bracket. When power is supplied to
the motor, the conveyor draws the angled bracket forward, dragging
the dross on the conveyor and over the edge of the solder
reservoir. The conveyor motor is preferably driven by a computer 32
such that the dross removal apparatus 10 can operate automatically
with or without operator intervention. Alternatively, the conveyor
motor 16 can be controlled by a switch. Preferably, the conveyor
motor 16 is computer controlled through timers with overload
protection for the device.
[0016] The conveyor 22 or other dross removal mechanism removes the
dross from the solder reservoir, sends it over chute 17 and
deposits it into a container or a dross separation device 34 for
further processing. One embodiment of the dross separation device
34, which is shown in FIGS. 1 and 2, includes a first portion 36
and a second portion 38. The first and second portions are movable
in relation to one another such that the dross recovered from the
solder reservoir 12 can be compressed to remove any usable molten
solder. For example, the first portion 36 of device 34 can include
a pivot 40 or hinge and be connected to a piston 42 or cylinder
that is driven by a motor 43. The second portion 38 can include
holes 44 of an appropriate size such that molten solder drops 45
flow through the holes and drops into a receptacle 46.
[0017] As shown in FIG. 2, the dross separation device 34 can
include an ejection device 48 that can include, for example, a
first portion 50 for ejecting the solder depleted dross, and a
piston 51 or cylinder that is driven by a motor 52. The ejection
device 48 can eject dross by moving outwardly in the direction of
the dross separation device 34 after the first portion 36 is opened
such that it is pivoted outwardly from the second portion 38. A
conveyor chute 19 for depositing the dross into the dross
separation device 34 can also be provided.
[0018] FIG. 3 shows an embodiment of the automatic dross removal
apparatus 60 that uses a dross separation device 62 which separates
the dross into receptacle 64 and reusable solder into receptacle
46. The dross separation device 60 can be a device such as the
dross muncher manufactured by the company Solet located in the
United Kingdom. Alternatively, dross separation device 60 could be
some other manufactured device.
[0019] FIGS. 4 and 5 show a second embodiment of the automatic
dross removal apparatus 70. The apparatus 70 has a solder reservoir
72 and a dross skimmer 74 having one end 77 protruding into the
reservoir 72 for moving or pushing the dross that is directed
towards it. The apparatus 70 also has a means for moving the dross
within the reservoir towards the skimmer 74 such as one or more
pumps 76 and pressure nozzles 78, which use channels to direct the
dross to the skimmer 74. The nozzle 78 has a main wave nozzle
entrance and exit side weir chambers 80 that are connected
internally via tubing allowing more even flow and to increase the
exit side flow to sufficiently flush out the dross 20 from the
nozzle. The dross flows out of the nozzles in one direction
flushing any dross with it, toward the removal mechanism. A gas
inert with solder such as nitrogen can be used to pressurize the
nozzle to remove and/or limit oxygen to further reduce dross
formation.
[0020] Like the dross removal apparatus 10, the dross removal
apparatus 70 can be driven by a motor 32 for automatically moving
the skimmer 74 to place the dross in a receptacle 75. The motor 32
is preferably driven by a computer 16 such that the dross removal
apparatus 70 can operate automatically with or without operator
intervention. Alternatively, the motor 32 can be controlled by a
switch. Preferably, the motor 32 is computer controlled through
timers with overload protection for the device.
[0021] FIGS. 6 and 7 show a second embodiment of the automatic
dross removal apparatus 110. The dross removal apparatus 110 is
generally similar to the dross removal apparatus 10 of FIG. 1 with
the exception that the conveyor 140 moves in an opposite direction
to the conveyor 14 in a direction shown by arrow 115. As shown in
FIG. 6 and best in FIG. 7, the conveyor 140 has two endless chains
134 that support a plurality of L-shaped brackets 131. The brackets
131 preferably have one or more slots 136 to allow liquid solder
118 to pass therethrough.
[0022] The dross removal apparatus 110 includes a solder reservoir
112 and a conveyor 114 that is driven by a motor 116. The reservoir
112 contains liquid solder 118 which has dross 120 forming on its
top surface. A conveyor 122 has one end protruding into the solder
reservoir 112 to skim the dross 120 from the surface of the solder
118, push it up the surface of ramp 119 and dump it into receptacle
175. Alternatively, the dross could be placed in a dross separation
device as shown in either FIGS. 2 or 3. The conveyor 114 is driven
by a motor 116 which drives a sprocket 130 that engages and drives
the endless belt or chain of the conveyor. The conveyor can have
one or more brackets 131, such as an angle bracket. When power is
supplied to the motor, the conveyor draws the angled bracket in the
direction of arrow 115, and drags the dross on the ramp 119 and
over the edge of the solder reservoir. The conveyor motor 116 is
preferably driven by a computer 132 such that the dross removal
apparatus 110 can operate automatically with or without operator
intervention. Alternatively, the conveyor motor 116 can be
controlled by a switch. Preferably, the conveyor motor 116 is
computer controlled through timers with overload protection for the
device.
[0023] It should be understood that the foregoing is illustrative
and not limiting and that obvious modifications may be made by
those skilled in the art without departing from the spirit of the
invention. Accordingly, reference should be made primarily to the
accompanying claims, rather than the foregoing specification, to
determine the scope of the invention.
* * * * *